The present invention relates generally to gripping features of hand-held articles. More particularly, the present invention relates to a grip element which is made from a soft, readily deformable material but which also is easy to manufacture and easy to assemble on a hand-held article.
Various hand-held articles are manufactured from smooth hard materials which are inexpensive and amenable to standard manufacturing processes. In order to increase comfort during gripping of the hand-held article and/or to decrease possible slippage because of the smoothness of the material, various grip elements have been designed for placement on the gripping portion of the hand-held article. Because such grip elements are provided to address different problems or consumer needs, a variety of different grip elements with different properties are available.
For instance, for purposes of increased comfort to consumers who grip a hand-held article very tightly, grip elements of soft foam are provided to permit ready deformation of the grip element and resulting enhanced comfort during gripping thereof. Other types of grip elements with low durometers (hardnesses) are known, such as on the Dr. Grip(copyright) writing instrument manufactured by Pilot(copyright) Corporation of America, of Trumbull Conn., and the PhD(trademark) writing instrument manufactured by Sanford, of Bellwood, Ill. However, to permit ready handling of known soft grip elements during manufacture and to facilitate assembly on the hand-held article, such soft grip elements require more material than is really necessary to achieve the desired enhanced comfort, thus increasing size or bulk as well as material costs. Moreover, insertion of a thick-walled grip element over the gripping section of a hand-held article results in a hand-held article significantly bulkier than would be the case without such grip element.
However, thin-walled tubular elements formed from very soft materials are difficult to handle for various reasons. For instance, the thin wall easily collapses on itself, requiring additional supporting and manipulating devices to permit insertion over a hand-held article. If the tubular element is transported in bulk, such as in a vibrating bowl, then the plurality of tubular elements collapse in transit, requiring manipulation to recreate their tubular configuration. Moreover, if the material is so soft that it has a high coefficient of friction, the collapsed walls may stick to each other to a certain degree, further complicating the handling of the tubular element.
In addition, if a grip element is designed to reduce slippage, such characteristic may backfire by interfering with ready sliding over the exterior of a hand-held article into the desired position on the article. A thin-walled grip element may stick to itself and wrinkle during insertion, further impeding insertion over the hand-held article.
Formation of the grip element directly on the gripping section of the hand-held article is one solution to the above-described problem of mounting a separately formed soft grip element onto a hand-held article. However, such solution has its drawbacks as well. If a molding process, such as a two-shot injection molding process, is used then the grip element is molded over a substrate which is typically the hand-held article itself. Because the hand-held article typically has a unique shape, the requisite mold complexity for such molding is relatively high, with accompanying high costs. The resulting mold process would likewise be expensive in order to control the high tolerances and critical features necessary to create a substrate with the desired features. For example, if the grip element is to be provided on a writing instrument, then the substrate is a writing instrument body which may have particular features requiring a complex, and thus expensive, mold. Moreover, if the substrate is the entire hand-held article, then only a limited number of mold cavities can be used per cycle for a given mold or press size.
Thus, it would be desirable to form a grip element from a material soft enough to provide the desired enhanced comfort while configuring the grip element to be readily assembled over the gripping section of the hand-held article.
In accordance with the principles of the present invention, a grip element configured for positioning over a hand-held article is formed with at least two layers. The layers of the grip element include an outer layer formed from a soft, readily compressible and deformable material and a support structure formed from a relatively rigid material capable of maintaining the desired shape of the grip element. Preferably, the outer layer is also resilient and the support structure is also flexible. In addition, the thickness of the support structure is selected to be the lowest thickness possible for maintaining the desired configuration of the grip element without collapsing on itself. Thus, the grip element is easily handled and/or manipulated for insertion over a gripping section of a hand-held article.
The grip element may be formed by providing the support structure in the desired shape of the finished grip element and then providing the outer layer over the formed support structure. Because the support structure is capable of maintaining the desired shape of the grip element, the outer layer need only be thick enough to impart the desired grip enhancing properties. Accordingly, a relatively thin outer layer which would likely not be manipulable on its own is supported by the underlying support structure and thus is readily manipulable. The resulting grip element thus has properties and characteristics which would not have been achievable with an outer layer as thin as provided if the support layer were not also provided as in accordance with the present invention.
In one embodiment, the grip element is formed as a tubular element having a longitudinal extent shorter than the longitudinal extent of the hand-held article onto which the grip element is to be provided. In particular, the grip element is preferably configured to be positioned at only a gripping section of the hand-held article and thus need only be long enough to occupy such region. For example, the grip element may be a tubular element of sufficient length for at least two fingers to contact grip element to grip the hand-held article. Since such length typically is not much greater than two inches (approximately 5 cm), if the grip element is formed by a molding process, a higher number of cavitation molds may be used per mold cycle for a given mold press size to result in a higher productivity rate.
These and other features and advantages of the present invention will be readily apparent from the following detailed description of the invention, the scope of the invention being set out in the appended claims.